beatmania IIDX(ビートマニア ツーディーエックス,Bītomania Tsūdiekkusu?) is a series of rhythm video games, that was first introduced by Konami in Japan on February 26, 1999.[2]IIDX has since spawned 24 arcade releases and 14 console releases on the Sony PlayStation 2.[3] It is the sequel to the beatmania game series,[4] and part of the Bemani line of music games.[5] A PC release titled beatmania IIDX INFINITAS has been announced, and began alpha testing in September 2015.[6]

In IIDX games, players recreate the musical score of songs available to them through the use of a DJ simulating controller.[7] The player must coordinate their hands in order to hit the correct keyboard buttons, spin the turntable, or a combination of both in correspondence to color-coded notes that approach the judgement bar displayed on screen.[8] Notes are divided on screen by columns which separate them accordingly to match the seven buttons and the turntable on the DJ simulating controller. As a result of hitting notes, different sounds are then produced throughout a songs duration. Correctly hitting notes will produce an accurate musical score, while incorrectly hitting notes will produce inaccuracies and mistakes in the music.

Starting from beatmania IIDX 17 SIRIUS, two new note types are added. Charge Notes is a note that must be pressed and released on the right time, while Backspin Scratch is a scratch note which require the player to spin the disc in a direction, then spinning it in the opposite direction at the end. Both are valued two combos; one for the beginning note and one for the ending note. beatmania IIDX 23 copula introduced a variation called Hell Charge Notes, which refill the gauge when held down but rapidly deplete it when not. Unlike regular Charge Notes, they can be pressed at any time, though missing the timing window will still break the player's combo.

Like most BEMANI titles, Beatmania IIDX has Extra Stage and One More Extra Stage songs, commonly known as ES and OMES respectively. When Extra Stage was introduced in beatmania IIDX 3rd Style, there was no new song to unlock, and the player simply got to play an extra song. beatmania IIDX 7th Style was the first to have an unlockable song only available on Extra Stage, and also introduced the One More Extra Stage. Obtaining the secret ES and OMES required meeting certain requirements during a session of play. beatmania IIDX 13 DistorteD was the first title with an Extra Stage system exclusive to players using an e-AMUSEMENT pass; it also included multiple Extra Stages that had to be cleared under certain requirements to unlock the One More Extra Stage.

beatmania IIDX 14 GOLD saw the return of the standard ES and OMES songs, alongside another multiple Extra Stage system. The setup of having two systems per game (standard system and e-AMUSEMENT system) continued until beatmania IIDX 18 Resort Anthem, where the standard ES and OMES stood alongside a new song unlock system tied to a player's e-AMUSEMENT pass. beatmania IIDX 19 Lincle brought back the multiple Extra Stage system, in the form of Lincle Kingdom, while retaining the standard ES and OMES setup. beatmania IIDX 20 tricoro replaces the standard Extra Stage with "LIMIT BURST", which allows seven different Extra Stage songs to be played. There are no One More Extra Stages for LIMIT BURST, and so far, the only OMES was Plan 8, part of Tricoro's first song unlock system, LEGEND CROSS.

Most Extra Stage songs debut in their respective Beatmania IIDX games, but there are some Extra Stage songs (esp. from the multiple Extra Stage systems) that are crossovers from other BEMANI titles; for example, beatmania IIDX 20 tricoro's LIMIT BURST system is largely made up of notably difficult songs from other games. Examples include "neu" from pop'n music 15 ADVENTURE, "JOMANDA" from jubeat copious, and "New Decade" from Dance Dance Revolution X2, which got a specially cut version of the song for its IIDX chart.

The beatmania IIDX cabinet has many standard features that are found in traditional arcade cabinets such as a widescreen display, powerful speakers, and start buttons. Also, unique to IIDX cabinets are the effector buttons and sliders, a bass platform transducer, marquee, and DJ simulating controller. The effector buttons and sliders allow the player to control the volume levels within the game and manipulate the music by adding additional sound effects. The bass platform vibrates beneath the player's feet to the beat of the music being played. The marquee is a series of sixteen-segment displayLEDs, used to display game information and scores during gameplay.

beatmania IIDX controls consist two sets of seven keys on each player's side, along with two turntables. The turntable for the left player's side is to the left of the keys, while the one on the right player's side is to the right.

Each set of keys is arranged in a pattern of four white keys beneath three black keys. The black keys are offset from the white keys so that each pair of adjacent white keys has a black key above and in between them. This arrangement mimics the F, F#, G, G#, A, A#, B keys on a musical keyboard, though beatmania keys, being about twice as long as they are wide, do not resemble piano keys. The keys are commonly numbered 1 through 7, from left to right. The four white keys are numbered 1, 3, 5, and 7; the three black keys are numbered 2, 4, 6.

Since 9th Style, the game has featured integration with Konami's e-Amusement platform, which uses a card inserted at the beginning of the game to save stats, scores, allow customization, and track scores in comparison to previous plays and against others over the internet. From 9th Style to Happy Sky (12th), this was by way of a magnetic card and reader. From Distorted onwards the newer type Contactless smartcard Konami e-Amusement Pass system has been used. 9th Style did not require an internet connection to use a subset of the e-Amusement functionality, but 10th and on required an internet connection to function, which must be provided by a subscription from Konami. e-Amusement is not available outside of the primary markets for IIDX (Japan and Asia, with the exception of select locations in the United States), which has left imported machines outside of Asia without full access to hidden songs and extra stages due to the increasing functionality and integration of e-Amusement in more recent styles. However, new songs from e-Amusement enabled styles can still be accessed on console versions (which can be imported from Japan).

Konami also released home versions of IIDX for the PlayStation 2 console in Japan. The home versions are known as CS (consumer software or console) styles, while the arcade versions are known as AC (arcade cabinet or arcade) styles. The CS games can be played with a DualShock controller or with a special controller from Konami that recreates the arcade experience. Konami manufactures two forms of home controllers, which are known as Konami Official Controllers (KOC) and Arcade Style Controllers (ASC). The KOC, pictured above, is much cheaper than the ASC, but is smaller than the ASC. In addition, KOCs look very different from ASCs and have a smaller space between the turntable and the keys. Konami purports the ASCs to be "arcade-accurate," in that they both resemble and feel like a controller on an arcade machine. For example, the controller itself is much larger and has the turntable further away from the keys. Both styles have a detachable key panel that can be placed to the left or the right of the turntable as the player desires. Aftermarket controllers are also readily available, often containing lit turntables and keys.

Each CS style corresponds to an AC style of the game and usually contains every song that debuted on its respective AC style, with the exception of certain licensed songs on 1st-3rd AC (released collectively as 3rd CS) that Konami was unable to secure the rights to again. In addition, CS styles may feature a selection of "revivals" - songs that appeared on previous AC or CS styles, "preview songs" - songs that appear on AC styles that do not yet have corresponding CS styles, and "CS exclusive" songs that appear only on CS styles. As of October 2009, CS versions of 3rd Style through Empress have been released (note that 3rd CS contains songs from 1st through 3rd AC; thus, there are no 1st style, 2nd style, or Substream CS titles); additionally, there is a PC title, Beatmania IIDX Infinitas, that doesn't correspond to any AC style however, is very closely related to Sirius in look and feel.

Music is an integral part of the beatmania IIDX series. Featuring a wide selection of genres and artists, both licensed and in-house, the Beatmania IIDX series is well known for its original music. Konami produces an original soundtrack of each game, usually a few months after release, due to the appeal of the music. Konami also releases original albums by Beatmania IIDX artists through its online store, Konamistyle. It's also a tradition that Konami crossovers some songs from other Bemani games such as Pop'n Music or Dance Dance Revolution.

Each new AC release typically features around 60 new songs, with a selection of songs returning from previous versions. The current release, beatmania IIDX 23 copula, features a library of over 700 songs. CS releases feature all of the new songs of their corresponding AC versions (with limited exceptions), 5-10 CS exclusive songs, around 25 "revival" (returning) songs, and 1-3 preview songs, for a total of around 90-100 songs. Arcade versions run from a hard drive, rather than a DVD, and thus have more space in which to store data.

Songs often include music videos when played, although only some songs contain dedicated videos. Some songs contain generic videos shared by multiple songs, and some of these have additional animated graphics overlaid atop them.

The beatmania IIDX series has been released in the home video game market in addition to its arcade releases. To date, the only video game system to have seen a IIDX game is the Sony PlayStation 2. There are currently sixteen games that have been released for the Japanese PlayStation 2 and one game for the American PlayStation 2 (beatmania).